US20070276185A1 - Endoscope, endoscopic apparatus, and examination method using endoscope - Google Patents

Abstract

An endoscope includes an insert section to be inserted into the body cavity, an illumination window for directing illumination light therethrough and an observation window for observing an illuminated internal portion of the body cavity, arranged at a distal end portion of the insert section, and a blood flow changing section for changing a blood flow of blood flowing through a vessel in a near-surface region of a living organ inside the body cavity by providing one of a temperature change and vibration energy.

Description

BACKGROUND OF THE INVENTION
• 1. Field of the Invention
• The present invention relates to an endoscope to be inserted in a body cavity appropriate for observing vessels, an endoscopic apparatus, and an examination method of using the endoscope.
• 2. Description of the Related Art
• Recently, endoscopes have been widely used in the medical field. Surgeons use the endoscopes to find and examine a lesion.
• For example, cancers, as an example of lesion, tend to develop and cluster in vessels including a capillary vessel in a near-surface region of a living organ. Using an endoscope, a surgeon determines the presence or absence of a capillary vessel in the near-surface layer of the living organ and observes a network of the capillary vessel using the endoscope. The use of the endoscope in this way is becoming an effective method to determine whether a lesion is a cancer.
• Thus, observing vessels containing capillary vessels in the near-surface layer of the living organ should be easy. However, the capillary vessel is too tiny to observe. More specifically, since the capillary vessel appears and disappears in synchronization with heart beat, it is difficult to observe it.
• United States Patent Application Publication No. 2004/0266713 discloses means for promoting the supply of blood flow by using hypodermic injection.
• United States Patent Application Publication No. 2004/0019120 discloses a method of administering a hyperosmotic agent for blood flow speed control.
SUMMARY OF THE INVENTION
• An endoscope of one embodiment of the present invention includes an insert section to be inserted into the body cavity, an illumination window for directing illumination light therethrough and an observation window for observing an illuminated internal portion of the body cavity, arranged at a distal end portion of the insert section, and a blood flow changing section for changing a blood flow of blood flowing through a vessel in a near-surface region of a living organ inside the body cavity by providing one of a temperature change and vibration energy.
• An endoscopic apparatus of another embodiment of the present invention includes an endoscope including an insert section to be inserted into the body cavity, an illumination window for directing illumination light therethrough and an observation window for observing an illuminated internal portion of the body cavity, arranged at a distal end portion of the insert section, and a blood flow changing section for changing a blood flow of blood flowing through a vessel in a near-surface region of a living organ inside the body cavity by providing one of a temperature change and vibration energy, and a light source for supplying the illumination light to the endoscope.
• An examination method of one embodiment of the present invention includes a blood flow changing step for causing vessels including capillary vessels in the near-surface of a living organ in a body cavity to change blood flow by providing a temperature change to the surface of the living organ with a temperature changer, and an observation step of observing one of a vessel and blood flow changed in the blood flow changing step with the endoscope.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 illustrates the entire configuration of an endoscopic apparatus of a first embodiment of the present invention.
• FIG. 2 is a block diagram illustrating in detail the endoscopic apparatus ofFIG. 1.
• FIG. 3 illustrates the configuration of two filter sets provided to a rotating filter.
• FIG. 4 illustrates spectral characteristics of each filter forming two filter sets ofFIG. 3.
• FIG. 5 is a block diagram illustrating a video processor.
• FIG. 6 is a flowchart illustrating operation of the present embodiment.
• FIGS. 7A and 7B diagrammatically illustrate the structure of a near-surface region of a mucous membrane and operation of an NBI observation mode.
• FIG. 8 diagrammatically illustrates a display example of a monitor screen which is shown when the mucous membrane is observed.
• FIG. 9 illustrates transmission characteristics of a filter set of a first modification for use in the NBI observation mode.
• FIG. 10 illustrates transmission characteristics of the filter set of a second modification for use in the NBI observation mode.
• FIG. 11 illustrates the configuration of the endoscopic apparatus of a modification.
• FIG. 12 is a configuration diagram illustrating an endoscopic apparatus in accordance with a second embodiment of the present invention.
• FIG. 13 is a configuration diagram illustrating a major portion of an endoscopic apparatus in accordance with a third embodiment of the present invention.
• FIGS. 14A through 14C illustrate operation of the third embodiment.
• FIG. 15 is a configuration diagram illustrating a major portion of an endoscopic apparatus in accordance with a fourth embodiment of the present invention.
• FIGS. 16A and 16B illustrate operation of the endoscopic apparatus of the fourth embodiment that allows observation in the NBI mode.
• FIG. 17 is a flowchart illustrating operation of a first modification of the fourth embodiment.
• FIG. 18 illustrates the configuration of a distal end portion of an electronic endoscope in accordance with a second modification of the fourth embodiment.
• FIG. 19 illustrates the configuration of an endoscopic apparatus in accordance with a fifth embodiment of the present invention.
• FIG. 20 diagrammatically illustrates spectral characteristics of a light source.
• FIG. 21 illustrates a mucous membrane that is observed during the NBI mode.
• FIG. 22 diagrammatically illustrates the configuration of a light source of a first modification of the fifth embodiment.
• FIG. 23 diagrammatically illustrates spectral characteristics of a filter ofFIG. 22.
• FIG. 24 diagrammatically illustrates the configuration of a light source of a second modification of the fifth embodiment.
• FIG. 25 is a flowchart illustrating operation of the second modification.
• FIG. 26 diagrammatically illustrates the configuration of a major portion of an endoscopic apparatus in accordance with a sixth embodiment of the present invention.
• FIG. 27 is a flowchart illustrating operation of the sixth embodiment.
• FIG. 28 diagrammatically illustrates the configuration of a major portion of the endoscopic apparatus as a modification of the sixth embodiment of the present invention.
• FIG. 29 illustrates the configuration of a distal end portion of an endoscopic apparatus in accordance with a seventh embodiment of the present invention.
• FIG. 30 illustrates the configuration of a major portion of a modification of the seventh embodiment of the present invention.
• FIG. 31 diagrammatically illustrates the configuration of a distal end portion of an endoscopic apparatus in accordance with an eight embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTSFirst Embodiment
• FIGS. 1 through 11 are related to a first embodiment of the present invention.FIG. 1 illustrates the entire configuration of an endoscopic apparatus of the present invention,FIG. 2 is a block diagram illustrating in detail the endoscopic apparatus ofFIG. 1,FIG. 3 illustrates the configuration of two filter sets provided to a rotating filter,FIG. 4 illustrates spectral characteristics of each filter forming two filter sets ofFIG. 3,FIG. 5 is a block diagram illustrating a video processor, andFIG. 6 illustrates operation of the present embodiment.
• FIG. 7 diagrammatically illustrates operation of an NBI observation mode in the first embodiment,FIG. 8 diagrammatically illustrates a display example of a monitor screen which is shown when a mucous membrane is observed,FIG. 9 illustrates transmission characteristics of a filter set of a first modification for use in the NBI observation mode,FIG. 10 illustrates transmission characteristics of the filter set of a second modification for use in the NBI observation mode, andFIG. 11 illustrates the configuration of the endoscopic apparatus of a modification.
• One object of the present embodiment is to provide an endoscope, an endoscopic apparatus, and an examination method of using the endoscope for distinctly observing the state and structure of a vessel and a blood flow through the vessel such as capillary vessel running in a near-surface area of a living organ in a body cavity. A further object of the present embodiment is to provide an endoscope, an endoscopic apparatus, and an examination method of using the endoscope for allowing users to observe the surface of the living organ in the body cavity, and a capillary vessel in the near-surface area of the living organ. The other embodiments have the same objects.
• As shown inFIG. 1, anendoscopic apparatus1A of the first embodiment of the present invention includes anelectronic endoscope2 having image pickup means, anobservation apparatus5 including alight source3 for supplying illumination light to illumination light transmission means of theelectronic endoscope2, and asignal processor4A for performing signal processing for the image pickup means, and anobservation monitor6 for displaying a video signal output from theobservation apparatus5.
• Theelectronic endoscope2 includes anelongated insert unit8 to be inserted into a living organ7 (in a body cavity) of a patient or the like, anoperation unit9 arranged at the proximal end of theinsert unit8, anuniversal cable10 extended from theoperation unit9, and aconnector11 arranged at the proximal end of theuniversal cable10. Theconnector11 is detachably connected to theobservation apparatus5.
• Theinsert unit8 includes adistal end portion12, a flexiblycurvable portion13 arranged at the proximal end of thedistal end portion12, and aflexible portion14 extending to the distal end of theoperation unit9 from the proximal end of thecurved portion13. Theoperation unit9 is provided with acurvature knob15. Using thecurvature knob15, a user such as a surgeon can curve thecurvable portion13.
• Alight guide16 is inserted through the insert unit8 (as shown in enlargement ofFIG. 1). With theconnector11 connected to theobservation apparatus5, illumination light is supplied to a light incident end from thelight source3 as shown inFIG. 2.
• The illumination light transmitted by thelight guide16 is output in a forward direction from the light guide distal end face thereof fixed to an illumination window of thedistal end portion12, and then illuminates the side of amucous membrane7aas a portion of the livingorgan7 to be observed.
• Anobjective lens17, secured to the observation window arranged next to the illumination window on thedistal end portion12, focuses an optical image of themucous membrane7ailluminated. A charge-coupled device (hereinafter CCD)18 as a solid-state image pickup device is arranged at a focus position, and theCCD18 photoelectrically converts the focused optical image into an electrical image. Theobjective lens17 and theCCD18 form animage pickup unit19 as the image pickup means.
• An image signal, obtained as a result of photoelectrical conversion of theCCD18, is signal processed into a standard video signal (image signal) by thesignal processor4A in theobservation apparatus5 and is then output to theobservation monitor6.
• Atool insertion port20, arranged near the distal end of theoperation unit9, communicates with achannel21. A tool, such as biopsy forceps may be inserted through thechannel21 from thetool insertion port20 and then an end portion of the forceps is projected out of thechannel21 to perform biopsy.
• Theelectronic endoscope2 includes atubular passage22 that runs longitudinally through theinsert unit8 and sends a thermal medium to the distal end thereof. The thermal medium fed through thetubular passage22 is sprayed from a distal end opening22aof thetubular passage22 toward themucous membrane7a.
• Thetubular passage22 is routed through theinsert unit8, theoperation unit9, and theuniversal cable10, and then reaches apipe sleeve22b(seeFIG. 2) attached to theconnector11. With theconnector11 detachably engaged with theobservation apparatus5, thepipe sleeve22bis connected to athermal medium feeder23 in theobservation apparatus5.
• FIG. 2 illustrates thelight source3 for generating the illumination light, thesignal processor4A and thethermal medium feeder23 all housed in theobservation apparatus5.
• Thelight source3 includes alight source unit24 for generating observation light in a wide range covering a visible-light region, from ultraviolet light to near infrared light. Thelight source unit24 may be a xenon lamp, a halogen lamp or the like.
• Thelight source unit24 is powered from apower supply25 for light generation. Arranged in front of thelight source unit24 is arotating filter27 rotated by amotor26 as shown inFIG. 3.
• As shown inFIG. 3, therotating filter27 has a dual structure, namely, includes two sets offilters28 and29, one on an inner ring portion and the other on an outer ring portion.
• The first filter set28 on the inner ring portion includes three filters of R1, G1, and B1 for standard observation, and the second filter set29 on the outer ring portion includes three filters R2, G2, and B3 for special observation purposes for vessel observation, more specifically for narrow-band imaging (hereinafter NBI). The first filter set28 and the second filter set29 are set for spectral transmittances for respective imaging purposes.
• More specifically, filters28a,28b, and28cfor allowing light rays in wavelength regions of red (R1), green (G1), and blue (B1) for normal imaging to pass therethrough are circularly arranged, and outside these filters28a,28b, and28c, filters29a,29b, and29cfor allowing light rays in wavelength regions of R2, G2, and B2 to pass therethrough are arranged.
• FIG. 4 illustrates spectral transmission characteristics of each filter of the first filter set28 and the second filter set29 ofFIG. 3 with wavelengths. The filters of R1, G1, and B1 forming the first filter set28 ofFIG. 4 typically have the same characteristics as R, G, and B filters widely used for light source devices for field sequential scanning.
• In contrast, the R2, G2, and B2 filters forming the second filter set29 are different in characteristic from the R, G, and B filters widely used for the light source device for field sequential scanning, and have narrow half-band width values Whr, Whg, and Whb. Although R2, G2, and B2 fall within the wavelength ranges of R, G, and B, respectively, the center frequencies of R2, G2, and B2 are deviated from the center frequencies of the R, G, and B light so that the resulting wavelengths of R2, G2, and B2 are appropriate for observing a vessel structure in the near-surface region of themucous membrane7aas described later.
• That is, when themucous membrane7ais illuminated by the light rays having passed through the R2, G2, and B2 filters, transmission depth (penetration transmission) becomes different from one ray to another.
• Thus, a captured image of the livingmucous membrane7ailluminated with the filtered light rays responds to the transmission depth of the light with the wavelength. By displaying the images with different colors, regions different in transmission depth are displayed in different colors.
• Thelight source3 includes afilter identifier circuit31. Thefilter identifier circuit31 identifies which one of the inner ring filter set and the outer ring filter set is arranged in an illumination optical path of thelight source unit24 ofFIG. 2, thereby identifying the light ray illuminating a region to be observed.
• Thelight source3 also includes a rotatingfilter switching mechanism32. The rotatingfilter switching mechanism32 selectively sets the first filter set28 on the inner ring portion and the second filter set29 on the outer ring portion in the illumination optical axis that extends from thelight source unit24 to the light input end face of thelight guide16.
• During the standard observation mode, the rotatingfilter switching mechanism32 shifts the entirerotating filter27 in the illumination light axis so that a light beam P1 (represented by solid line inFIG. 3) from thelight source unit24 is in alignment with the inner ring first filter set28.
• During the NBI observation mode, the rotatingfilter switching mechanism32 shifts the entirerotating filter27 in the illumination light axis so that a light beam P2 (represented by broken line inFIG. 3) from thelight source unit24 is in alignment with the outer-ring second filter set29.
• The rotatingfilter switching mechanism32 is designed to shift themotor26 and thefilter identifier circuit31 relative to thelight source unit24. Alternatively, thelight source unit24 may be shifted in an opposite direction.
• Themotor26 rotates under the control of amotor control circuit33.
• Light rays of the wavelength regions Ri, Gi, and Bi (i=1 or 2) passed through therotating filter27 and separated time-sequentially are incident on the input end of thelight guide16, guided by thelight guide16 to the output end thereof, output in a forward direction from the output end thereof, and illuminates an area to be observed, such as the livingmucous membrane7a.
• To identify the light beam illuminating the observation area, a filter identification signal F1 output from thefilter identifier circuit31 in thelight source3 is transferred to atiming generator34 via themotor control circuit33 that controls themotor26. Thetiming generator34 outputs to aCCD driver35 and the like a timing signal synchronized with the filter identification signal F1.
• A returning light beam reflected from the observation area such as the illuminated livingmucous membrane7ais focused on theCCD18, and then photoelectrically converted by theCCD18. TheCCD18 is supplied with a drive pulse from theCCD driver35 in asignal processor4A via a signal line, and reads an electrical signal (video signal) responsive to an image of the livingmucous membrane7aphotoelectrically converted in response to the drive pulse.
• The drive pulse is thus used to accumulate charge onto theCCD18 during an open period of the rotating filter27 (period throughout which an observation light beam illuminates the observation area) and reads the charge accumulated on theCCD18 during a light blocking period (period throughout which the observation light beam does not illuminate the observation area).
• FIG. 3 does not show a blocking area for simplicity. In practice, however, a blocking area is arranged between the R1 filter and the B1 filter. When the light beam is directed to the light blocking area, it becomes a light blocking period.
• The charge read from theCCD18 is supplied to apre-amplifier36 arranged in theelectronic endoscope2 or theobservation apparatus5 via a signal line as an electrical signal. A video signal amplified by thepre-amplifier36 is supplied to aprocessor circuit37 where signal processing including γ correction and white balance process and the like is performed. The resulting signal is then A/D converted into a digital signal by an A/D converter38.
• Aselector circuit39 causes three memories, namely, afirst memory41a, asecond memory41b, and athird memory41carranged corresponding to red (R), green (G), and blue (B) to selectively to store the digital video signal.
• Color signals Ri, Gi, and Bi respectively stored on thefirst memory41a, thesecond memory41b, and thethird memory41c(represented by SR, SG, and SB inFIG. 5) are concurrently read, and input to avideo processor42. Thevideo processor42 performs video processing on the color signals.
• An output signal from thevideo processor42 is converted into analog color signals (represented by R, G, and B for simplicity inFIG. 2) by a D/A converter43, and then output as R, G, and B color signals to the observation monitor6 via an input-output interface (I/O)44. The observation monitor6 displays the observation area such as the livingmucous membrane7aand the like in color.
• Theendoscopic apparatus1A further includes a rotatingfilter control device45 in thelight source3. When a user operates anobservation mode switch46 for switching observation modes of theelectronic endoscope2, the rotatingfilter control device45 outputs to the rotating filter switching mechanism32 a rotating filter switch command signal C1 corresponding to the switching of observation mode.
• At the moment therotating filter27 is switched, the rotatingfilter control device45 issues a video process change command signal C2 to thevideo processor42 to change video processing.
• Thesignal processor4A in theobservation apparatus5 includes thetiming generator34 for generating timings of the entire system. Thetiming generator34 maintains themotor control circuit33, theCCD driver35, theselector circuit39, etc. in synchronization.
• Theoperation unit9 in theelectronic endoscope2 includes anobservation mode switch46 including a scope switch for issuing a switch command of observation mode.
• When the user operates theobservation mode switch46, a mode switch command signal C3 is transferred to the rotatingfilter control device45. The rotatingfilter control device45 then outputs the rotating filter switch command signal C1 or the like to switch from the standard observation mode to the NBI observation mode or from the NBI observation mode to the standard observation mode.
• Athermal medium feeder23 arranged in thelight source3 includes apump48 for conveying a medium such as air or water prior to heating from amedium supply47, apipe49 serving as a passage for conveying the medium from thepump48 to thepipe sleeve22b, and aheater50 serving as a heater unit wrapped around a part of an outer circumference of thepipe49. Theheater50 performs a heating operation with power for heating supplied from aheater power supply51.
• The medium passing through thepipe49 where theheater50 is wrapped around is heated to a fixed temperature by theheater50 and conveyed to atubular passage22 within theelectronic endoscope2 via thepipe sleeve22b.
• Atemperature sensor53 is arranged on the outer circumference of thepipe49 close to the end of theheater50 to detect the temperature of the medium heated by theheater50. Information about the temperature detected by thetemperature sensor53 is input theheater power supply51.
• Theheater power supply51 controls heater power or the like so that the temperature detected by thetemperature sensor53 becomes a temperature set in atemperature setter55 to be discussed later slightly higher than a temperature of the inside of a body cavity, namely, a normal temperature of the livingmucous membrane7a.
• Atemperature sensor53 is also arranged in the vicinity of the distal end opening22aof thetubular passage22. Temperature information about a temperature detected by thetemperature sensor53 is input to aprotective circuit54. Theprotective circuit54 determines whether a temperature detected by thetemperature sensor53 is equal to or lower than a threshold value. The threshold value is used to determine whether the temperature of the medium detected by thetemperature sensor53 is too high relative to the livingmucous membrane7a.
• When the detected temperature of the thermal medium is above the threshold temperature value, theprotective circuit54 stops the feeding of the medium from thepump48 while also stopping the operation of theheater power supply51. Theprotective circuit54 thus performs a protective operation to stop the spraying of the thermal medium above the threshold temperature value.
• The user operates thetemperature setter55 connected to theheater power supply51, and can thus variably set a temperature at which theheater50 performs the heating operation. Taking into consideration a temperature drop caused while passing through thetubular passage22 in the temperature of the thermal medium set as a result of heating by theheater50, the user sets a temperature slightly higher than a temperature of the medium the user desires to spray from the distal end opening22a.
• Theprotective circuit54 operates independent of the setting operation of thetemperature setter55, and performs the protective function thereof overriding the function of thetemperature setter55.
• The rotatingfilter control device45 controls the operation of thethermal medium feeder23 in response to the switching from the standard observation mode to the NBI observation mode.
• More specifically, in response to the switching from the standard observation mode to the NBI observation mode, the rotatingfilter control device45 switches on theheater power supply51 and switches on thepump48. Conversely, in response to the switching from the NBI observation mode to the standard observation mode, the rotatingfilter control device45 switches off theheater power supply51 and switches off thepump48.
• FIG. 5 illustrates the specific configuration example of thevideo processor42.
• R, G, andG gain adjusters56a,56b, and56creceive, from thememories41a,41b, and41c, color signals SR, SG, and SB captured under illumination light rays Ri, Gi, and Ri (more specifically, color signals R, G, and B captured under the illumination light rays R1, G1, and B1 and color signals R, G, and B captured under the illumination light rays R2, G2, and B2). The R, G, andG gain adjusters56a,56b, and56cgain adjust the color signals SR, SG, and SB at gains set by gain parameters Pa, Pb, and Pc from a gainparameter changing circuit57, and then output gain adjusted signals to a D/A converter43.
• The gainparameter changing circuit57 outputs, to the R, G, andG gain adjusters56a,56b, and56c, gain parameters Pa, Pb, and Pc responsive to the video process change command signal C2 from the rotatingfilter control device45.
• In this case, thevideo processor42 includes again parameter memory58. In response to the inputting of the video process change command signal C2, the gainparameter changing circuit57 applies to the gain parameter memory58 a gain parameter read request command signal C4 for reading the gain parameters stored beforehand on thegain parameter memory58.
• The gainparameter changing circuit57 causes thegain parameter memory58 to output a corresponding gain parameter set C5, and supplies the R, G, andG gain adjusters56a,56b, and56cwith the gain parameters Pa, Pb, and Pc forming the gain parameter set.
• The major functions of the present embodiment are discussed below. When the user issues a switch command to switch from the standard observation mode to the NBI observation mode, thethermal medium feeder23 becomes initiated. Then, the thermal medium is then sprayed onto the observation area such as the livingmucous membrane7aor the like from the distal end opening22aof thetubular passage22 arranged in theelectronic endoscope2. A temperature change is provided to the surface of the observation area to a temperature state higher than a normal temperature state.
• With the temperature shifting to a higher temperature, vessels in the near-surface region of the observation area expand, thereby increasing blood flow through the vessels, and thus allowing the vessels to be more easily observed. In accordance with the present embodiment, theelectronic endoscope2 has a function of blood flow changing means that provides a change to the vessels in the near-surface region of the observation area by spraying the thermal medium from the distal end opening22a. In this case, since the capillary vessels run in the near-surface region of a living organ, the blood flow of the capillary vessels increases, thereby allowing the user to more easily observe the capillary vessels.
• Operation of the present embodiment is described below with reference to a flowchart of an examination method ofFIG. 6. The examination method includes as major steps a blood flow changing step by warming the livingmucous membrane7aduring the NBI observation mode and an endoscopic observation step with the blood flow changed.
• As shown inFIG. 1 orFIG. 2, a surgeon connects theelectronic endoscope2 to theobservation apparatus5 to perform endoscopy, and turns on an unshown power switch of theobservation apparatus5. With power on, the rotatingfilter control device45 sets illumination and observation state (image processing) for the standard observation mode in step S1 ofFIG. 6.
• More specifically, the rotatingfilter control device45 performs a control process to place the first filter set28 in alignment with the illumination optical axis. In this condition, a white light ray from thelight source unit24 passes through the first filter set28 having the same characteristics as those of the standard R, G, and B filters shown inFIG. 4. Thelight source3 supplies frame-sequential illumination light rays of R1, G1, and B1 to thelight guide16, thereby illuminating the observation area such as the livingmucous membrane7awith the frame-sequential illumination light rays of R1, G1, and B1.
• The observation area illuminated with the frame-sequential illumination light rays of R1, G1, and B1 is image-captured by theCCD18 of theimage pickup unit19. The R, G, and B video signals (color signals) output from theCCD18 are converted into digital signals by thesignal processor4A, and then successively stored onto thefirst memory41a, thesecond memory41b, and thethird memory41c.
• The R, G, and B color signals temporarily stored on thefirst memory41a, thesecond memory41b, and thethird memory41care also concurrently read, and input to thevideo processor42. Thevideo processor42 performs image processing on the R, G, and B color signals.
• The image processed color signals are converted into analog color signals by the D/A converter43, and then displayed as a color image of the observation area of the livingorgan7 on theobservation monitor6.
• During the standard observation mode, the first filter set28 covering the entire visible light range is used to reproduce a natural color. Subsequent to step S1 ofFIG. 1, the rotatingfilter control device45 monitors switching to the NBI observation mode in step S2.
• The surgeon may switch to the NBI observation mode to observe more in detail the network of the vessels including the capillary vessels in the near-surface region of the observation area. To switch to the NBI observation mode, the surgeon operates theobservation mode switch46.
• In response to the mode switch command signal C3 generated in response to the operation of theobservation mode switch46, the rotatingfilter control device45 detects the switch command to the NBI observation mode.
• In step S3, the rotatingfilter control device45 performs a control process to shift therotating filter27 to set the illumination state of the NBI observation mode. In this case, the second filter set29 in therotating filter27 is set to be in alignment with the illumination optical axis. The rotatingfilter control device45 thus switches the video processing of thevideo processor42 to the NBI observation mode.
• Further to the above description, the rotatingfilter control device45 outputs to the rotatingfilter switching mechanism32 the rotating filter switch command signal C1. The rotatingfilter switching mechanism32 shifts therotating filter27 upward inFIG. 2 (leftward inFIG. 3), thereby aligning the light beam P2 from thelight source unit24 to the second filter set29. With this condition set, thefilter identifier circuit31 detects the condition, thereby ending a rotating filer switch operation.
• During the NBI observation mode, the filters R2, G2, and B2 ofFIG. 4 have narrower half-band width values Whr, Whg, and Whb in light transmission characteristics than R1, G1, and B1, and luminance levels of resulting signals drop.
• Consequently, in response to the switching to the second filter set29, the rotatingfilter control device45 outputs the video process change command signal C2 to thevideo processor42. The rotatingfilter control device45 performs the control process to result in an image appropriate for examination, for example, by increasing the gains of the R, G, andG gain adjusters56a,56b, and56cto be higher than those for the standard observation mode.
• During the NBI observation mode in the present embodiment, gain setting is performed so that an image (component image) obtained under the illumination through the R2, G2, and G2 filters reaches a luminance level easy to discriminate when displayed in different colors (easy to discriminate taking into consideration the recognition function of humans to color).
• In accordance with the present embodiment, the rotatingfilter control device45 turns on the operation of thethermal medium feeder23 in step S4 in response to the setting in step S3. The thermal medium generated by thethermal medium feeder23 flows through thetubular passage22 of theelectronic endoscope2 and is then sprayed to the observation area from the distal end opening22a.
• Through the spraying of the thermal medium in step S5, the temperature of the vessels in the observation area rises and the vessels expand thereby causing the blood flow change to increase blood flow. The surgeon observes (examines) the vessels such as the capillary vessels and the blood flow with theelectronic endoscope2 with the blood flow increased (changed).
• Theprotective circuit54 monitors in step S6 whether the temperature of the thermal medium detected by thetemperature sensor53 is equal to or lower than the threshold value. If it is determined that the detected temperature is equal to or lower than the threshold value, processing returns to step S3 to observe the vessels with the blood flow increased during the NBI observation mode.
• Meanwhile, if the detected temperature is above the threshold value, theprotective circuit54 immediately turns off the operation of thethermal medium feeder23. With the feeding operation of thepump48 stopped, the spraying operation of the thermal medium from the distal end opening22aimmediately stops. Also, the supplying of the heater power from theheater power supply51 to theheater50 is cut off, and theheater50 stops heating. The protective operation is thus performed.
• The NBI observation mode is appropriate for observing the cross-sectional structure of the mucous membrane as shown inFIG. 7A.
• The near-surface region of the livingmucous membrane7a, such as a mucous membrane of the stomach, is now observed as the observation area.
• The typical cross section of the near-surface region of the mucous membrane is shown as inFIG. 7A. The mucous membrane includes a surface irregular structure, a capillary network at a near-surface layer, vessels larger than the capillary vessels at a layer slightly deeper, and a large-vessel network at a deeper layer.
• When the living mucous membrane is observed, the observed image preferably shows the structure of vessels in detail. By observing the structure of the capillary vessel at the near-surface layer, early detection of a lesion such as a cancer becomes easy.
• The light is used to observe the living mucous membrane in which vessels runs at the sub-layer. How the light penetrates the sub-surface layer depending on the wavelength thereof is shown inFIG. 7B. The shorter the wavelength of the visible light (blue light), the shallower the light penetrates the living organ. The longer the wavelength of the light (from green to red), the deeper the light penetrates the mucous membrane of the living organ.
• The filter elements R1, G1, and B1 of the first filter set28 for use in the standard observation mode have broad bands with wide half-band widths to cover the visible light region to achieve natural color reproduction as shown inFIG. 4. In these characteristics, light through the filter B1 as a short wavelength light contains light components in a wide wavelength range, and permit concurrent observation with a light ray having a shallow penetration depth and a light ray having an intermediate penetration depth.
• As a result, a B image thus contains a mixture of signals from the capillary vessels at the near-surface layer to the vessels at the intermediate layer.
• In contrast, the filter B2 of the second filter set29 having a narrow-band width Whb limits the wavelength range of the light rays, and as a result, in comparison with the light ray B1 having broad characteristics, the ratio of light rays having a shallow penetration depth in the living mucous membrane becomes large. The image resulting from the B2 light rays increases contrast of the capillary network on the surface, and permits the near-surface structure to be observed easily.
• From the graph plotting the spectral characteristics of the R1, G1, and B1 filters of the first filter set28 and the R2, G2, and B2 filters of the second filter set29 ofFIG. 4, the filters for the NBI observation mode have narrow half-band values Whr, Whg, and Whb, and the center wavelengths are adjusted so that the bands are separated with no portion thereof overlapping each other.
• The band width or half-band width value Whg of the G2 is set to be narrower than the filter G1, and the band of the G2 is separated from the band of the filter B2 along the wavelength axis. In the same way as in the B2 light rays, the half-band width Whg of the wavelength of the filter G2 is set to be narrow. The difference of the image from the filter B2 becomes distinct. The image from the filter G2 does not reflect the surface structure and the capillary vessels, while distinctly showing the vessel structure at the intermediate layer.
• The band width or half bandwidth Whr of the filter R2 is set to be narrower than the filter R1. The band of the filter R2 is separated from the filter G2 along the wavelength axis. In this way, the image through the R2 filter reflects large vessels at the deeper layer alone.
• The captured images through the bands of the filters R2, G2, and B2 are signal processed in a way similar to the standard observation mode except the gain adjustment through thevideo processor42. The resulting image is displayed in color as RGB color signals on theobservation monitor6.
• In this case, information about the vessel structure in depth direction is represented with color difference and resulting color differences are synthesized in color display. Unlike the standard observation mode, the vessel structure information is reproduced clearly.
• More specifically, the capillary network at the near-surface layer is displayed yellow (G and R colors appearing with only B color absorbed), the vessel network at the intermediate layer is displayed magenta to red, and the large vessel at the deep layer is displayed blue-tinged.
• Therefore, the vessel structure running at different depths as illustrated inFIG. 8 are diagrammatically shown different in color on the monitor screen of theobservation monitor6. The network of the vessels at different depths are clearly identified from the image.
• The signals output to R, G, and B channels of the observation monitor6 are switchably or selectively set so that the network of the capillary vessels may be displayed at a color tone preferred by the user.
• Also, when the apparatus is switched to the NBI observation mode in the present embodiment as described above, a heated medium such as heated (warmed) air or water is sprayed onto the surface of the livingmucous membrane7a. The near-surface capillary vessels expand and are observed more easily by the user than when the heated medium is not sprayed.
• In accordance with the present embodiment, an endoscopic image appropriate for standard observation is thus obtained. With the filter set switched, the network of the vessels at different depths in the near-surface layer of the livingmucous membrane7acan thus observed.
• Since in particular, a large temperature change is provided to the capillary vessels running at the near-surface layer, the network of the vessels is more easily observed. The surgeon can smoothly examine the inside of the body cavity with theelectronic endoscope2.
• As a first modification of the second filter set29, the filter set may have characteristics ofFIG. 9. In the first modification, the filter G2 in the second filter set29 ofFIG. 4 is arranged as a filter R2, and a filter G2 and a filter B2 having narrow half-bandwidths are shifted to a shorter wavelength side than the filter R2.
• The filter G2 is slightly shifted to a longer wavelength side than the filter G2 ofFIG. 4 and the filter B2 is slightly shifted to a shorter wavelength side than the filter B2 ofFIG. 4.
• The second filter set29 as the first modification is appropriate for observing in detail the surface roughness structure to the vessel network at the intermediate depth layer in different colors.
• A filter set having characteristics ofFIG. 10 may be used as a second modification of the second filter set29. In the second modification, all filters R2, G2, and B2 are arranged in a short wavelength range so that scattering and absorption of light rays at the near-surface layer of the living mucous membrane are detected at high gain. These characteristics are appropriate for detecting early stage cancer developed at the near-surface layer of the livingmucous membrane7a.
• During the NBI observation mode, thelight source3 may supply two narrow-band illumination light rays to thelight guide16. For example, as shown inFIG. 23, thelight source3 may supply two narrow-band illumination light rays G2 and B2 during the NBI observation mode.
• In this case, thesignal processor4A may output two color signals corresponding to the illumination light rays to the observation monitor6 to display the image in two colors. Furthermore, thesignal processor4A may output one of the two color signals to the two channels of the observation monitor6 (in this case, an endoscopic image is displayed in three colors).
• In the above description, thetubular passage22 for spraying the thermal medium to the observation area is arranged within theelectronic endoscope2. A structure such as an endoscopic apparatus1B ofFIG. 11 may also be acceptable.
• The endoscopic apparatus1B employs an electronic endoscope2B that includes a thermalmedium spray tube59 detachably loaded to thetool insertion port20 in theelectronic endoscope2A.
• FIG. 11 illustrates an electronicendoscopic portion2A that permits the thermalmedium spray tube59 to be detachably loaded into achannel21.
• In the configuration as shown inFIG. 11, asleeve59bat the proximal end of the thermalmedium spray tube59 is detachably engaged with an end of a connection portion of thepipe49 of thethermal medium feeder23. Thetemperature sensor53 is also arranged on the distal end opening of the thermalmedium spray tube59.
• When thesleeve59bis connected to the end of the pipe49 (seeFIG. 2), a detected signal of thetemperature sensor53 is supplied to theprotective circuit54 via an unshown electrical connection. The rest of the structure of the endoscopic apparatus1B is identical to theendoscopic apparatus1 ofFIGS. 1 and 2. In this case, the electronic endoscope2B has substantially the same functions as theelectronic endoscope2.
• In the configuration ofFIG. 11, the electronic endoscope2B is embodied by loading the thermalmedium spray tube59 to an existingelectronic endoscope2A. For this reason, this modification advantageously increases applications.
• As shown inFIG. 11, the end portion of the thermalmedium spray tube59 is projected out of the end opening of thechannel21. Alternatively, the end portion of the thermalmedium spray tube59 is placed within thetool insertion port20 and thechannel21 is used as a passage of the thermal medium. In this case, the end opening of thechannel21 serves as a sprayer of the thermal medium.
• In the first embodiment, thetemperature sensor53 is arranged to detect the temperature of the thermal medium when the heated (warmed) medium is sprayed. As in a sixth embodiment to be discussed later, atemperature sensor94 for detecting the temperature of the livingmucous membrane7ain a non-contact fashion may be arranged.
Second Embodiment
• Referring toFIG. 12, a second embodiment of the present invention is described below.FIG. 12 diagrammatically illustrates the configuration of anendoscopic apparatus1C in accordance with the second embodiment of the present invention.
• In accordance with the first embodiment, thethermal medium feeder23 is arranged in thelight source3, and the thermal medium from thethermal medium feeder23 is passed through thetubular passage22 in theelectronic endoscope2 and then sprayed to the observation area. In contrast, theendoscopic apparatus1C includes in alight source3B a thermalmedium feeder23B, the medium of which is not yet heated, and a heater in thetubular passage22 in anelectronic endoscope2C. The heated medium is sprayed from the distal end opening22aof thetubular passage22.
• The thermalmedium feeder23B ofFIG. 12 does not include theheater50 and theheater power supply51 ofFIG. 2.
• Meanwhile, thetubular passage22 in theelectronic endoscope2C includes a heater andtemperature sensor unit61 into which a heater and a temperature sensor are integrated as a unitary body. Although the heater and the temperature sensor are integrated into a unitary body herein, the heater and the temperature sensor may be arranged as separate units.
• When theconnector11 is connected to theobservation apparatus5, the heater andtemperature sensor unit61 is connected to acontroller63 in the thermalmedium feeder23B viaelectrical junctions62.
• In response to the inputting of the mode switch command signal C3 from theobservation mode switch46, thecontroller63 controls the heater andtemperature sensor unit61 and thepump48 in medium feeding. Thecontroller63 is also connected to the rotatingfilter control device45B.
• In accordance with the first embodiment, the rotatingfilter control device45 also controls thethermal medium feeder23. In the second embodiment, thecontroller63 controls medium feeding and medium heating while the rotatingfilter control device45B controls switching of therotating filter27 in response to the control process of thecontroller63. The rest of the structure of the second embodiment is identical to the first embodiment.
• Unless otherwise particularly noted, the operation in the standard observation mode in the second and subsequent embodiments remains unchanged from that in the first embodiment.
• The operation of the second embodiment is similar to the operation of the first embodiment. In accordance with the second embodiment, thelight source3B connected to theelectronic endoscope2C is reduced in size. Since the heater is arranged in theelectronic endoscope2C in accordance with the second embodiment, the temperature drop of the thermal medium occurring in the way to the distal end opening22ais reduced.
• The remaining advantages of the second embodiment are substantially identical to those of the first embodiment.
• In a modification of the second embodiment, the heater may be fabricated of a spiral member arranged in theinsert unit8, and the thermal medium flowing through thetubular passage22 in the spiral member is thus heated.
• In accordance with the second embodiment, the heater andtemperature sensor unit61 in thetubular passage22 is integrally arranged with theelectronic endoscope2C in a unitary body. Alternatively, the modification of the first embodiment (structure described with reference toFIG. 11) may be applied. More specifically, a tube housing the heater andtemperature sensor unit61 is detachably inserted in thechannel21 of theelectronic endoscope2A ofFIG. 11.
Third Embodiment
• A third embodiment of the present invention is described below with reference toFIG. 13.FIG. 13 diagrammatically illustrates the configuration of a major portion of anendoscopic apparatus1D of the third embodiment of the present invention. In accordance with the third embodiment, a medium, such as a thickener, changing viscosity thereof with temperature is used.
• An electronic endoscope2D sprays, from the distal end thereof, a medium in a liquid state to the observation area such as the livingmucous membrane7a. The sprayed medium has the function of raising the surface and near-surface region of the observation area in temperature, thereby increasing the blood flow. In addition to this function, the medium shifts to a large viscosity state when the medium drops in temperature, and tends to stay on the observation area. The medium thus has the function of covering the surface of the observation area and maintaining temperature (temperature insulation).
• Theendoscopic apparatus1D of the third embodiment includes agel supply65 instead of themedium supply47 in theendoscopic apparatus1A ofFIG. 2. Thegel supply65 stores a transparent thickener (or a solvent dissolving the thickener). The thickener becomes low in viscosity and fluid in a high temperature condition while becoming high in viscosity and gelated in a low temperature condition.
• Thegel supply65 is connected to aheater66 composed of a heater and a heater power supply. Theheater66 stores athickener66athat is almost in a fluid state as a result of being heated to a temperature slightly higher than the temperature of the livingorgan7.
• When thepump48 is operated, thefluid thickener66aheated by theheater66 is fed to thetubular passage22C in the electronic endoscope2D via thepipe49. The electronic endoscope2D employs thetubular passage22C instead of thetubular passage22 in theelectronic endoscope2 of the first embodiment. Thetubular passage22C serves as a thickener passage that conveys thefluid thickener66ato the end thereof, and the distal end opening22asprays thefluid thickener66a.
• In the third embodiment, theheater66 is always in an operational state, and when switched to the NBI observation mode, thecontroller63 sets thepump48 from off to on. When switched to the standard observation mode, thepump48 is turned off.
• With thepump48 turned on, thefluid thickener66ais sprayed from the distal end opening22aof thetubular passage22.
• Thethickener66a, when sprayed onto the livingmucous membrane7a, raises the surface layer of the livingmucous membrane7ain temperature as previously described in connection with the first embodiment, and expands the capillary vessels and the like for easy observation.
• The rest of the configuration of the third embodiment remains unchanged from the above-described embodiments.
• Operation of the third embodiment in response to the switching to the NBI observation mode is described below with reference toFIGS. 14A through 14C.
• With the operation mode switched to the NBI observation mode, thecontroller63 activates thepump48.
• Thefluid thickener66aheated by theheater66 passes through thepipe49 and thetubular passage22C of theelectronic endoscope2A and is then sprayed from the distal end opening22aas described inFIG. 14A.
• More specifically, thefluid thickener66ais sprayed from the distal end opening22aonto the livingmucous membrane7aas the observation area.
• Thethickener66asprayed on the livingmucous membrane7araises the surface layer of the livingmucous membrane7ain temperature and expands the capillary vessels for easy observation as previously described in connection with the first embodiment.
• In this case, thethickener66athen drops in temperature, and becomes high in viscosity. As shown inFIG. 14B, thethickener66abecomes gelated into athickener66bwith viscosity increased from the fluid state thereof. Thethickener66btends to stay on the surface of the livingmucous membrane7a.
• Moreover, thethickener66bcovers the surface of the livingmucous membrane7a, thereby maintaining the inner area at a high temperature.
• As shown inFIG. 14B, thegelated thickener66btends to stay on the mucous membrane and keep temperature. With the temperature maintenance property of thethickener66b, the amount of sprayed medium is reduced, and the state in which the capillary network is observed in detail is thus maintained.
• After observing the livingmucous membrane7a, thethickener66b, if having biocompatibility, can be left there.
• If a removable operation to remove thethickener66bis performed, a warm water is sprayed onto thethickener66bthrough an unshown pipe to restore thefluid thickener66a. A distal end opening of thechannel21 having the function of a suction pipe suctions thefluid thickener66aand discharges the suctionedthickener66ato outside the body cavity.
• In the above description, thepump48 liquefies thethickener66aand conveys thefluid thickener66athroughtubular passage22C and sprays thethickener66afrom the distal end opening22a.
• In this case, depending on type, thethickener66amay have no large viscosity even in its gelated state. In such a case, thethickener66ais heated in the gelated state thereof to a temperature slightly higher than the temperature of the livingmucous membrane7a.Such thickener66ais sprayed from the distal end opening22ausing pressure of thepump48.
Fourth Embodiment
• A fourth embodiment of the present invention is described below with reference toFIG. 15.FIG. 15 diagrammatically illustrates the configuration of a major portion of anendoscopic apparatus1E in accordance with the fourth embodiment. In the fourth embodiment, a temperature control device (or heater device) is arranged at the end of adistal end portion12 of theendoscopic apparatus1E. The temperature control device provides a temperature change to the livingmucous membrane7awith the temperature control device in contact with the livingmucous membrane7a. A blood flow changes in the area of contact, and vessels there are easy to observe.
• Anelectronic endoscope2E of the fourth embodiment is without thetubular passage22 for allowing the thermal medium to pass therethrough in theelectronic endoscope2 of the first embodiment (for example, theelectronic endoscope2A ofFIG. 11). In theelectronic endoscope2E, aPeltier device71 is arranged at the end face of thedistal end portion12 as a heater device for temperature control.
• Thetemperature sensor53 is arranged next to thePeltier device71 to detect the temperature of thePeltier device71.
• ThePeltier device71 is connected to aDC power supply72 arranged in theobservation apparatus5 via a power source line. When the NBI observation mode is set under the control of thecontroller63, theDC power supply72 supplies DC power to thePeltier device71.
• Thecontroller63 controls supplying of the DC power to thePeltier device71 so that thePeltier device71 reaches a temperature set by the user on thetemperature setter55. The temperature detected by thetemperature sensor53 is input to thecontroller63 to be used for temperature control while also being input to theprotective circuit54. When the detected temperature rises above a threshold value, theprotective circuit54 turns off theDC power supply72 so that no DC power is supplied to thePeltier device71. Thecontroller63 is connected to the rotatingfilter control device45B.
• Since the fourth embodiment does not use the thermal medium described in connection with the first embodiment, no thermal medium feeder means is required in theobservation apparatus5.
• Operation of the fourth embodiment is described below.
• When a surgeon switches to the NBI observation mode, thecontroller63 activates theDC power supply72 while sending a signal to the rotatingfilter control device45B for illumination for the NBI observation mode. TheDC power supply72 supplies DC power to thePeltier device71. TheDC power supply72 under the control of thecontroller63 controls DC power so that the temperature of thePeltier device71 becomes the temperature set by thetemperature setter55.
• Thereafter, the surgeon moves the end face of theinsert unit8 to the livingmucous membrane7aas shown inFIG. 16A, thereby putting the end face in contact with the livingmucous membrane7a.
• Then, the surface area of the livingmucous membrane7ais heated by thePeltier device71, and then rises in temperature. As previously described in connection with the first embodiment, the blood flow in the near-surface region of the livingmucous membrane7aincreases.
• Subsequently, the surgeon then moves theinsert unit8 backward, and observes the livingmucous membrane7ain the NBI observation mode with the end face of theinsert unit8 in close range to the livingmucous membrane7aas shown inFIG. 16B. The fourth embodiment also provides the same advantages as those of the first embodiment. A heating device such as a heater may be used instead of thePeltier device71.
• Next, a first modification of the fourth embodiment is described below. In the fourth embodiment, thePeltier device71 is heated (warmed) by supplying DC power thereto. The first modification permits thePeltier device71 to switch between heating and cooling.
• By operating thetemperature setter55, the surgeon can set a temperature higher than the temperature of the livingmucous membrane7aor lower than the temperature of the livingmucous membrane7a. In this case, thecontroller63 supplies DC power to thePeltier device71 with the polarity of the DC power of theDC power supply72 inverted. Thus, the end face of thePeltier device71 absorbs heat, thereby functioning as cooling means.
• Operation of the temperature control of thecontroller63 is illustrated inFIG. 17. With the NBI observation mode set, thecontroller63 starts a temperature control operation. In step S1, thecontroller63 retrieves information regarding temperature set by thetemperature setter55.
• In the next step S12, thecontroller63 determines whether the set temperature is higher than the temperature of the livingmucous membrane7a.
• If it is determined that the set temperature is higher than the temperature of the livingmucous membrane7a, thecontroller63 supplies thePeltier device71 with DC power at a polarity for heating in step S13a, thereby operating thePeltier device71 with the end face thereof in a heating state.
• Meanwhile, if it is determined that the set temperature is lower than the temperature of the livingmucous membrane7a, thecontroller63 supplies in step S13bthePeltier device71 with DC power at a polarity inverted from the polarity for heating, thereby operating thePeltier device71 with the end face thereof in a cooling state.
• Subsequent to step S13a, thecontroller63 retrieves in step S14ainformation regarding the temperature detected by thetemperature sensor53, and then determines whether the detected temperature reaches the set temperature. Heating operation is performed until the detected temperature almost reaches the set temperature.
• Subsequent to step S13b, thecontroller63 retrieves in step S14binformation regarding temperature detected by thetemperature sensor53 and then determines whether the detected temperature reaches the set temperature. Cooling operation is performed until the detected temperature almost reaches the set temperature.
• Meanwhile, if the set temperature has been almost reached in step S14aor S14b, thecontroller63 continuously performs the temperature determination.
• The present modification has the function of providing a change in the blood flow by giving a temperature change to the livingmucous membrane7anot only by heating but also by cooling. In the case of the cooling operation, the blood flow is reduced and the endoscopic image also changes accordingly. The vessels are observed by viewing the change. After the livingmucous membrane7ais cooled by placing thePeltier device71 into contact therewith, vessel observation may be performed as the blood flow increases while the livingmucous membrane7ais rising in temperature.
• Next, a second modification of the fourth embodiment is described below with reference toFIG. 18.FIG. 18 illustrates a distal end side of anendoscopic apparatus2F of the second modification. The second modification is without thePeltier device71 in theelectronic endoscope2E ofFIG. 15. Theobservation apparatus5 is without the DC power supply. The second modification uses the end face of thelight guide16 as heating means (warming means). Thelight guide16 includes at the end face thereof anillumination lens16a.
• In a similar way as previously described with reference toFIG. 16A, the livingmucous membrane7ais heated by putting the end face of thelight guide16 into contact with the livingmucous membrane7a. The livingmucous membrane7ais observed with the blood flow increased. When thelight guide16 is placed in contact with the livingmucous membrane7a, the temperature of the heated livingmucous membrane7ais detected by thetemperature sensor53, and the livingmucous membrane7ais protected from excessive temperature rise above a threshold value.
Fifth Embodiment
• A fifth embodiment of the present invention is described below with reference toFIG. 19.FIG. 19 illustrates the configuration of anendoscopic apparatus1G of the fifth embodiment.
• Using far-infrared light rays, the fifth embodiment sets in a non-contact manner the blood flow to a state easy to observe.
• Theendoscopic apparatus1G ofFIG. 19 includes aelectronic endoscope2G without thetubular passage22 unlike theelectronic endoscope2 of the first embodiment.
• Theobservation apparatus5 ofFIG. 19 includes alight source3G having no thermalmedium feeder23. Thelight source3G includes alight source unit24′ that emits light rays in a visible light region ofFIG. 20 and a far-infrared region longer than 4 μm. As shown inFIG. 20, no light rays are emitted from within a range from about 1 μm to about 4 μm, but the present invention is not limited to this characteristic.
• A second filter set29′ has filter characteristics having the far infrared region ofFIG. 20 in addition to the transmittance characteristic of the second filter set29 ofFIG. 4. More specifically, filters R2′, G2′, and B2′ forming the second filter set29′ have the transmittance characteristics that permit the light rays within the far infrared region ofFIG. 20 to pass, in addition to the transmittance characteristics of the filters R2, G2, and B2 ofFIG. 4, respectively.
• Alight guide16′ of theelectronic endoscope2G includes far infrared transmission means for transmitting the far infrared light ray in addition to the visible light ray. Thelight guide16′ may be a hollow structure having an internal surface reflecting light. Thelight guide16′ irradiates the livingmucous membrane7awith the far infrared light ray transmitted from one end thereof.
• The rest of the fifth embodiment remains unchanged from the previously described first embodiment.
• Operation of the fifth embodiment is identical to that of the first embodiment in connection with the standard observation mode. With the operation mode switched to the NBI observation mode, the rotatingfilter control device45 performs a control process so that the second filter set29′ is aligned with the illumination optical axis as shown inFIG. 19.
• Then, since the filters of the second filter set29′ have the transmittance characteristics permitting the far infrared light ray to pass therethrough in addition to the transmittance characteristics of the second filter set29 ofFIG. 4, the observation area is irradiated with the far infrared light ray. More specifically, the observation area is irradiated with the far infrared light ray and the NBI light ray.
• Since the far infrared light ray has a property to heat the livingorgan7, the observation area irradiated with the far infrared light ray is heated, and the blood flow through the vessels including the capillary vessels increases. Therefore, with the operation mode switched to the NBI observation mode, the capillary vessels are viewed in a state easy to observe. The fifth embodiment provides the same advantages as those of the first embodiment and the other embodiments.
• The far infrared light ray may be considered to be warming means for imparting vibration energy to the livingmucous membrane7a(if each molecule forming the livingmucous membrane7ais considered as grating, grating vibration is provided to each grating).
• Next, a first modification of the fifth embodiment is described below with reference toFIG. 22.FIG. 22 diagrammatically illustrates the configuration of alight source3H as the first modification.
• In the first modification, therotating filter27 ofFIG. 19 is composed of only a first filter set28′ (represented byreference numeral28′ for simplicity inFIG. 21).
• The first filter set28′ is provided with the transmittance characteristics of R1′, G1′, and B1′ permitting the far infrared light ray to pass therethrough in addition to the transmittance characteristics of R1, G1, and B1 ofFIG. 4.
• A secondrotating filter81 is arranged to face the first filter set28′ in the illumination optical axis. The secondrotating filter81 includes afilter82 permitting a visible light ray to pass therethrough and afilter83 permitting an NBI light ray and a far infrared light ray to pass therethrough.
• As shown inFIG. 23, thefilter83 has NBI observation filter characteristics permitting light in narrow bands of G2 and B2 therethrough, and characteristics permitting the far infrared light ray therethrough. The NBI observation filter characteristics may be filter characteristics permitting light rays in narrow bands of R2, G2, and B2 therethrough.
• The rotatingfilter control device45 controls the angle of rotation of amotor84, thereby controlling the filters that are arranged in the illumination optical axis. During the standard observation mode, thefilter82 permitting the visible light ray to pass therethrough is arranged in the illumination optical axis, and the same operation as described in connection with the first embodiment is performed.
• During the NBI observation mode, the rotatingfilter control device45 performs the control process, thereby arranging thefilter83 in the illumination optical axis as shown inFIG. 22.
• In this case, since the first filter set28′ is rotated, only the far infrared light ray is passed if the R1′ filter is arranged in the illumination optical axis. If the G1′ filter is arranged in the illumination optical axis, the G2 light ray and the far infrared light ray are passed. If the B1′ filter is arranged in the illumination optical axis, the B2 light ray and the far infrared light ray are passed.
• Accordingly, the first modification has the operation and advantages similar to those described with reference toFIG. 19.
• FIG. 24 diagrammatically illustrates the configuration of a light source3I as a second modification. In thelight source3G ofFIG. 19, thelight source unit24′ includes a lamp having light emission characteristics covering the visible light region and the far infrared light region. In the second modification, the light source3I includes the (visible light emission)light source unit24 covering the visible light region and a far infraredlight source86 covering the far infrared light region.
• During the standard observation mode, the second modification has the configuration and operation identical to those discussed with reference toFIG. 19. With the operation mode switched to the NBI observation mode, the far infrared light ray from the far infraredlight source86 travels through ashutter87, and a half-mirror88 in the illumination optical axis, and then guided to thelight guide16′ along with the light ray having passed through the second filter set29 for NBI observation as shown inFIG. 24.
• The half-mirror88 may be arranged in the illumination optical axis only during the NBI observation mode or may be always arranged in the illumination optical axis.
• In the second modification, apulse irradiation switch46bis arranged next to theobservation mode switch46 in theelectronic endoscope2G. Operating thepulse irradiation switch46b, the surgeon irradiates the livingmucous membrane7awith the far infrared light ray thereby pulsed heating the livingmucous membrane7aduring the NBI observation mode.
• More specifically, operating thepulse irradiation switch46b, the surgeon sets a pulsed irradiation mode for intermittently irradiating the livingmucous membrane7awith the far infrared light ray. The pulsed irradiation mode provides to the livingmucous membrane7aa blood flow change different from a continuous irradiation mode.
• FIG. 25 is a flowchart of operation of the NBI observation mode. In response to a switch command to switch to the NBI observation mode, illumination and image processing state for the NBI observation mode are set in step S3 (as inFIG. 6).
• The rotatingfilter control device45 sets theshutter87 from off to on in step S21 in response to step S3, thereby allowing the far infrared light ray to enter thelight guide16′ together with the NBI observation light ray.
• Accordingly, from the end face of thelight guide16′ in theelectronic endoscope2G, the NBI observation light ray is directed together with the far infrared light ray to the observation area. In step S22, the observation area is heated by the far infrared light ray and the surgeon can thus observe the observation area with the blood flow increased.
• In step S23, the rotatingfilter control device45 monitors the operation of thepulse irradiation switch46b. If the surgeon wants to observe the observation area in pulsed heating, namely, heating alternately on and off, the surgeon operates thepulse irradiation switch46b.
• In step S24, the rotatingfilter control device45 turns on and off theshutter87 at periodic intervals. The surgeon can thus observe a change in the blood flow by pulsed heating with the far infrared light ray.
• In accordance with the second modification, the surgeon observes the capillary vessels by selecting between the continuous heating mode and the pulsed heating mode. The rest of the second modification remains unchanged from the fifth embodiment and has similar advantages as those of the fifth embodiment.
• In a modification to the arrangement ofFIG. 24, theelectronic endoscope2G includes thelight guide16 instead of thelight guide16′ and an separately arranged far infrared light transmitter for transmitting the far infrared light ray.
• When the NBI observation mode is set, the far infrared light ray from the far infraredlight source86 may be incident on the proximal end of the far infrared light transmitter. The far infrared light ray output from the distal end of the far infrared light transmitter may be then directed to the livingmucous membrane7a. In this case, the far infrared light transmitter may be integrally formed to theelectronic endoscope2G or may be detachably mounted in thechannel21.
• Atemperature sensor94 to be described in connection with a sixth embodiment, not arranged in theelectronic endoscope2G ofFIG. 19, may be used. The temperature of the livingmucous membrane7amay be detected in a non-contact fashion using thetemperature sensor94 and then monitored.
Sixth Embodiment
• A sixth embodiment is described below with reference toFIG. 26.FIG. 26 illustrates the configuration of a major portion of anendoscopic apparatus1J in accordance with the sixth embodiment of the present invention.
• When the NBI observation mode is set in the fifth embodiment, the livingmucous membrane7ais irradiated with the far infrared light ray. In the sixth embodiment, the livingmucous membrane7ais irradiated with a microwave rather than the far infrared light ray.
• Anelectronic endoscope2J of the sixth embodiment includes amicrowave irradiation device91 for directing a microwave arranged at the end of theelectronic endoscope2G ofFIG. 19.
• Themicrowave irradiation device91 is supplied with DC power or pulsed power from theDC power supply92 in theobservation apparatus5 via a pulse modulation circuit (simply referred to as “modulation” inFIG. 26)93. Themicrowave irradiation device91 thus generates a microwave continuously or in a pulsed form, thereby directing the microwave to the observation area such as the livingmucous membrane7a.
• With the microwave directed, water molecules in the livingmucous membrane7ain the observation area absorb vibration energy of an electromagnetic wave, i.e., the microwave, and are thus heated. Heat is also transferred to molecules, other than the water molecules, surrounding the water molecules. These molecules are also heated.
• Thetemperature sensor94 for detecting radiation temperature is arranged next to themicrowave irradiation device91. Thetemperature sensor94 detects the temperature of the observation area and then outputs the detected temperature to theprotective circuit54.
• The temperature sensor is composed of a thermopile, and detects the temperature of the observation area in a non-contact fashion. The temperature sensor is thus used to prevent the observation area from being heated at a predetermined temperature value or higher.
• Theprotective circuit54 switches off theDC power supply92 when the temperature detected by thetemperature sensor94 rises above the threshold value.
• Theobservation mode switch46 is connected to the rotatingfilter control device45. When theobservation mode switch46 issues a switch command to switch to the NBI observation mode, the rotatingfilter control device45 activates theDC power supply92. In this case, theDC power supply92 supplies DC power to themicrowave irradiation device91 via thepulse modulator circuit93.
• When thepulse irradiation switch46bis operated, the rotatingfilter control device45 controls to operate thepulse modulator circuit93 to supply pulsed DC power to themicrowave irradiation device91.
• A radiationangle changing device91afor switching a radiation angle of the microwave between a narrow angle and a wide angle is arranged at the front of themicrowave irradiation device91. The surgeon operates a radiationangle changing switch46cto set the radiation angle of the microwave to a narrow angle or a wide angle depending on an observation distance to the livingmucous membrane7a.
• The rotatingfilter control device45, receiving an operation signal of the radiationangle changing switch46c, controls the radiationangle changing device91aby switching on and off DC power from theDC power supply92. The DC power is normally cut off, and in this state, the radiationangle changing device91acauses the microwave to be directed at a narrow angle.
• The radiationangle changing device91ais, for example, a horn type waveguide that guides the microwave, generated by a semiconductor device, and radiates the microwave from an end opening. A horn portion of the waveguide is made of a shape-memory metal. The horn portion, when supplied with DC power, rises in temperature. With a shape-memory function of a high-temperature phase side of the shape-memory metal, the metal in a high-temperature phase side changes to a different shape in an opening angle (to a wider angle) different from a low-temperature phase side of the metal. The light source of the sixth embodiment, although not shown inFIG. 26, is identical in configuration to thelight source3 of the first embodiment, for example.
• Operation of the sixth embodiment is described below. The operation of the sixth embodiment remains unchanged from that of the first embodiment during the standard observation mode.
• With the operation mode switched to the NBI observation mode, the sixth embodiment operates as described in a flowchart ofFIG. 27. In steps S3 to S24′ inFIG. 27, the microwave is used instead of the far infrared light ray used as described with reference to corresponding steps in FIG.25. Steps inFIG. 27 modified from the corresponding steps inFIG. 25 are thus marked with the sign (′).
• Subsequent to step S24′ in the sixth embodiment, the rotatingfilter control device45 monitors in step S25 whether the radiationangle changing switch46cis operated. If the radiationangle changing switch46cis not operated, themicrowave irradiation device91 emits the microwave at a narrow angle.
• The surgeon typically observes the livingmucous membrane7awith thedistal end portion12 in theelectronic endoscope2J placed in close range with the livingmucous membrane7a. In contrast, to observe the livingmucous membrane7ato view a wide area at a longer range than an ordinary observation distance, the surgeon may operate the radiationangle changing switch46c.
• In this case, DC power is supplied to the radiationangle changing device91ain step S26, and the radiation angle of the microwave is switched to a wide angle. And, a wide area of the livingmucous membrane7ais irradiated with the microwave. That is, depending on the observation area of the livingmucous membrane7a, a heated area is also changed. Themicrowave irradiation device91 increases the blood flow in the vessels such as the capillary vessels in the heated area, thereby setting the livingmucous membrane7ain a state easy to view.
• In step S27, theprotective circuit54 monitors whether the temperature detected by thetemperature sensor94 is equal to or lower than the threshold value. If the detected temperature is equal to or lower than the threshold value, processing returns to step S22′. In this case, themicrowave irradiation device91 continues to irradiate the livingmucous membrane7awith the microwave.
• Meanwhile, if the temperature detected by theprotective circuit54 rises above the threshold value, theDC power supply92 is switched off in step S28, thereby stopping microwave irradiation.
• The energy level of the microwave directed in a pulse form with thepulse irradiation switch46boperated is set to a higher value than when the microwave is continuously directed. This increases the effectiveness of the function of increasing the blood flow with time. In this way, the capillary vessels or the like, become easier to observe.
• The sixth embodiment provides the same advantages as those of the second modification of the fifth embodiment. Furthermore, a range where the livingmucous membrane7ais heated (in other words, a range where the blood flow changes) can be modified. Thetemperature sensor94 ofFIG. 26 may be included in another embodiment so that the temperature of the livingmucous membrane7abeing heated is detected in a non-contact fashion to prevent the livingmucous membrane7afrom being heated at a predetermined temperature or higher.
• FIG. 28 illustrates the configuration of a major portion of anendoscopic apparatus1J′ as a modification.
• Theendoscopic apparatus1J′ includes anelectronic endoscope2J′ and anobservation apparatus5′. Theelectronic endoscope2J′ is identical to theelectronic endoscope2J except that nolight guide16 is contained and that three color light emitting diodes (LED)101 and two color light emitting diodes LED102 are arranged at thedistal end portion12.
• During the standard observation mode, under the control of the rotatingfilter control device45′, the threecolor LED101 emits light rays and during the NBI observation mode, the twocolor LED102 emits light rays.
• The threecolor LED101 successively emits frame-sequential illumination light rays by the first filter set28, namely, R1, G1, and B1 light rays, and the twocolor LED102 successively emits the illumination light rays by the second filter set29, namely, G2 and B2 light rays ofFIG. 23.
• The rotatingfilter control device45′ operates in almost the same way as the rotatingfilter control device45. More specifically, the rotating filter control device,45′ does not perform a rotating filter switching control process, but performs a switching control process for switching the illumination light rays in the same way as when the rotating filter is switched. The rotatingfilter control device45′ performs a switching control on thevideo processor42 although such a control process is not identified inFIG. 28.
• In this modification, themicrowave irradiation device91 is without the radiationangle changing device91a. Accordingly, theelectronic endoscope2J′ is without the radiationangle changing switch46c.
• The modification provides operations and advantages substantially identical to those of theendoscopic apparatus1J′ ofFIG. 26 except the operation of changing the radiation angle of the microwave.
• In the sixth embodiment, the living mucous membrane is irradiated with the microwave. Alternatively, the living mucous membrane may be irradiated with ultrasonic wave, such as ultrasonic microwave.
Seventh Embodiment
• A seventh embodiment of the present invention is described below with reference toFIG. 29.FIG. 29 illustrates the configuration of a distal end portion of anelectronic endoscope2K in accordance with the seventh embodiment of the present invention. The seventh embodiment includes amagnetic coil96 for applying magnetic energy instead of themicrowave irradiation device91 in the sixth embodiment.
• In this case, thetemperature sensor94 is not included herein. During the NBI observation mode, the livingmucous membrane7ais irradiated with magnetic energy generated by themagnetic coil96. The seventh embodiment increases the blood flow and facilitates observation of the capillary vessels or the like, by directing the magnetic energy to the livingmucous membrane7a.
• A modification of the seventh embodiment includes an externalmagnetic coil97 arranged external to theliving organ7 as shown inFIG. 30. The externalmagnetic coil97, powered by apower supply98, directs magnetic energy to theliving organ7. In this case, anelectronic endoscope2K′ to be inserted into the livingorgan7 is without themagnetic coil96 of theelectronic endoscope2K ofFIG. 28. Thepower supply98 is controlled by the rotatingfilter control device45.
• As shown inFIG. 30, the externalmagnetic coil97 also directs magnetic energy to a portion of the livingorgan7 observed by theelectronic endoscope2K′.
• During the NBI observation mode in the modification, magnetic energy is directed to the observation area observed by theelectronic endoscope2K′ from the outside, and vessels such as capillary vessels are observed with the blood flow therewithin increased.
• In the modification ofFIG. 30, the externalmagnetic coil97 arranged external to theliving organ7 directs the generated magnetic energy to theliving organ7. The present invention is not limited to this arrangement. For example, magnetic energy generating means such as themagnetic coil96 may be arranged external to theelectronic endoscope2K′.
Eighth Embodiment
• An eighth embodiment of the present invention is described below with reference toFIG. 31.FIG. 31 illustrates the configuration of a distal end portion of anendoscopic apparatus2L in accordance with the eighth embodiment of the present invention. In the eighth embodiment, acap99 is loaded to thedistal end portion12 in one of theelectronic endoscope2K′ ofFIG. 30 and theelectronic endoscope2A ofFIG. 11.
• During the NBI observation mode, theendoscopic apparatus2L suctions the surface of the livingmucous membrane7avia thechannel21. As shown inFIG. 31, the vessels in the portion of the livingmucous membrane7asuctioned into thecap99 are forced into stasis state for easy observation.
• With the eighth embodiment, vessels such as capillary vessels set to the easy-to-observe state thereof are observed using an existing electronic endoscope.
• In addition to means and methods of the above-described embodiments for changing the blood flow, the present invention also includes means and methods for changing the blood flow in vessels such as capillary vessels by providing a stimulation to the livingmucous membrane7a. For example, the livingmucous membrane7ais pressed and then released. Subsequent to the removal of the pressure, the livingmucous membrane7ais reddened. Taking advantage of this phenomenon, observation may be performed in the NBI observation mode after the removal of the pressure.
• The present invention also includes a mechanism in which the position of a body is changed in response to the switching of the operation mode to the NBI observation mode. With the position of the body changed, the blood flow is changed taking advantage that blood tends to easily flow in the direction of gravity. The observation of the vessels such as the capillary vessels and the blood flow through the vessels is thus facilitated during the NBI observation mode.
• In accordance with the above-referenced embodiments, a blood flow changer changes the blood flow through vessels including capillary vessels at the near-surface layer of the living organ in the body cavity, thereby facilitating observation of the vessel and the blood flow therethrough.
• A different embodiment may be constructed by combining parts of the above-referenced embodiments. For example, the heating device such as thePeltier device71 ofFIG. 15 and themicrowave irradiation device91 ofFIG. 26 may be mounted on a wire or a tube inserted through thechannel21 instead of being mounted on thedistal end portion12 of theinsert unit11.
• The present invention is not limited to the arrangement in which the blood flow changing means for changing the blood flow is integrated with the endoscope. The present invention also includes the arrangement in which the blood flow changing means is detachably mounted on the endoscope.
• When the operation mode is switched from the standard observation mode to the NBI observation mode in the above-referenced embodiments, the blood flow changing means for increasing the blood flow is operatively driven. The present invention is not limited to the arrangement in which the blood flow increasing is timed to the observation mode switching. The surgeon may turn on and off the blood flow changing means.
• Aswitch46dfor issuing a command to turn on and off themicrowave irradiation device91 forming the blood flow changing means may be arranged in theoperation unit9 ofFIG. 28 (as represented by broken line inFIG. 28).
• The operation signal of theswitch46dis input to thecontrol device45′. Thecontrol device45′ switches on and off power to be supplied to themicrowave irradiation device91 in response to the on/off operation signal (for starting and stopping the supply of power).
• This arrangement may be incorporated in another embodiment. For example, aswitch46dis arranged in the first embodiment ofFIG. 2, and in response to the on/off operation signal of theswitch46d, the heating power from theheater power supply51 to theheater50 is switched on and off and thepump48 is switched on and off.
• Having described the preferred embodiments of the invention referring to the accompanying drawings, it should be understood that the present invention is not limited to those precise embodiments and various changes and modifications thereof could be made by one skilled in the art without departing from the spirit or scope of the invention as defined in the appended claims.

Claims (51)

1. An endoscope for observing the inside of a body cavity, comprising:

an insert section to be inserted into the body cavity;

an illumination window for directing illumination light therethrough and an observation window for observing an illuminated internal portion of the body cavity, arranged at a distal end portion of the insert section; and

a blood flow changing section for changing a blood flow of blood flowing through a vessel in a near-surface region of a living organ inside the body cavity by providing a temperature change.

2. The endoscope according toclaim 1, wherein the blood flow changing section includes a medium sprayer that sprays a warmed medium onto the surface of the living organ in the body cavity.

3. The endoscope according toclaim 2, wherein the blood flow changing section sprays the warmed medium onto the living organ in the body cavity so that a temperature of a portion of the living organ where the medium is sprayed is kept.

4. The endoscope according toclaim 2, wherein the medium is a transparent medium with a viscosity thereof changing with temperature.

5. The endoscope according toclaim 1, wherein the blood flow changing section provides a temperature change to the surface and near-surface region of the living organ in a manner that the blood flow changing section is out of contact with the surface of the living organ in the body cavity.

6. The endoscope according toclaim 1, wherein the blood flow changing section provides a temperature change to the surface and near-surface area of the living organ in a manner that the blood flow changing section is in contact with the surface of the living organ in the body cavity.

7. The endoscope according toclaim 5, wherein the blood flow changing section comprises a far-infrared irradiator for irradiating the surface of the living organ with a far-infrared light beam.

8. The endoscope according toclaim 6, wherein the blood flow changing section comprises one of a Peltier device and a heater arranged in the distal end portion.

9. The endoscope according toclaim 1, comprising a switch for switching on and off operation of the blood flow changing section.

10. The endoscope according toclaim 1, comprising in the distal end portion a temperature sensor for detecting a temperature of the surface of the living organ in the body cavity.

11. The endoscope according toclaim 1, comprising in the distal end portion a temperature sensor for detecting a temperature of the surface of the living organ in the body cavity in a manner that the temperature sensor is out of contact with the surface of the living organ.

12. The endoscope according toclaim 5, further comprising a switch that intermittently provides the temperature change.

13. An endoscope for observing the inside of a body cavity, comprising:

an insert section to be inserted into the body cavity;

an illumination window for directing illumination light therethrough and an observation window for observing an illuminated internal portion of the body cavity, arranged at a distal end portion of the insert section; and

a blood flow changing section for changing a blood flow of blood flowing through a vessel in a near-surface region of a living organ inside the body cavity by providing vibration energy.

14. The endoscope according toclaim 13, wherein the blood flow changing section comprises a vibration energy irradiator for irradiating the surface of the living organ in the body cavity with vibration energy.

15. The endoscope according toclaim 14, wherein the blood flow changing section comprises a microwave irradiator for irradiating the surface of the living organ in the body cavity with microwave.

16. The endoscope according toclaim 13, wherein the blood flow changing section comprises a changer for changing a range of the vibration energy that is provided to the surface of the living organ in the body cavity.

17. The endoscope according toclaim 13, further comprising a switch for intermittently providing the vibration energy.

18. The endoscope according toclaim 13, comprising in the distal end portion a temperature sensor for detecting a temperature of the surface of the living organ in a manner that the temperature sensor is out of contact with the surface of the living organ.

19. An endoscopic apparatus for observing the inside of a body cavity, comprising:

an endoscope including an insert section to be inserted into the body cavity, an illumination window for directing illumination light therethrough and an observation window for observing an illuminated internal portion of the body cavity, arranged at a distal end portion of the insert section; and

a blood flow changing section for changing a blood flow of blood flowing through a vessel in a near-surface region of a living organ inside the body cavity by providing one of a temperature change and vibration energy.

20. The endoscopic apparatus according toclaim 19, wherein the blood flow changing section is mounted on the endoscope detachably or in an integrally fixed manner as a unitary body.

21. The endoscopic apparatus according toclaim 20, wherein the blood flow changing section is detachably mounted on a channel of the endoscope.

22. The endoscopic apparatus according toclaim 19, further comprising a light source for providing illumination light to the endoscope.

23. The endoscopic apparatus according toclaim 22, wherein the light source selectively outputs, through the illumination window, visible-light illumination light and narrow-band illumination light.

24. The endoscopic apparatus according toclaim 22, further comprising a switch for switching illumination light output through the illumination window between visible-light illumination light and narrow-band illumination light.

25. The endoscopic apparatus according toclaim 24, further comprising a controller for switching on and off operation of the blood flow changing section in response to the operation of the switch.

26. The endoscopic apparatus according toclaim 24, wherein the light source further comprises a far-infrared generator for generating far infrared light.

27. The endoscopic apparatus according toclaim 26, wherein the endoscope comprises a far infrared light transmitter for transmitting the far infrared light generated by the far-infrared generator to the distal end portion thereof, and a far-infrared light irradiator for irradiating the surface of the living organ in the body cavity with the far infrared light from the distal end portion of the far-infrared light transmitter.

28. The endoscopic apparatus according toclaim 24, wherein the blood flow changing section comprises a medium sprayer for spraying a warmed medium onto the surface of the living organ in the body cavity.

29. The endoscopic apparatus according toclaim 28, further comprising a temperature setter for setting a temperature to which the medium to be sprayed onto the surface of the living organ in the body cavity is warmed.

30. The endoscopic apparatus according toclaim 26, wherein the surface of the living organ in the body cavity is irradiated with the far infrared light together with the narrow-band illumination light in response to the operation of the switch.

31. The endoscopic apparatus according toclaim 26, wherein the light source selectively supplies the far infrared light and the visible-light illumination light to the endoscope by moving a filter that allows the far infrared light to pass therethrough.

32. The endoscopic apparatus according toclaim 19, comprising a temperature sensor for detecting a temperature of the surface of the living organ in which the blood flow changing section provides a change in the blood flow.

33. The endoscopic apparatus according toclaim 32, comprising a temperature monitor for monitoring whether the temperature detected by the temperature sensor rises above a predetermined temperature.

34. The endoscopic apparatus according toclaim 33, wherein the temperature monitor stops the operation of the blood flow changing section for blood flow change when the detected temperature rises above the predetermined temperature.

35. An examination method of using an endoscope inserted in a body cavity, comprising:

a blood flow changing step for causing vessels including capillary vessels in the near-surface of a living organ in a body cavity to change blood flow by providing a temperature change to the surface of the living organ in the body cavity with a temperature changer; and

an observation step of observing one of a vessel and blood flow changed in the blood flow changing step with the endoscope.

36. The examination method of using the endoscope according toclaim 35, wherein the blood flow changing step comprises a warming/cooling step of warming or cooling the surface of the living organ.

37. The examination method of using the endoscope according toclaim 35, wherein the blood flow changing step comprises a warming step of warming the surface and near-surface region of the living organ in a manner out of contact with the surface of the living organ.

38. The examination method of using the endoscope according toclaim 35, wherein the blood flow changing step comprises warming the surface and near-surface region of the living organ with a warmed medium or a warming element placed into contact with the surface of the living organ.

39. The examination method of using the endoscope according toclaim 35, wherein the blood flow changing step comprises starting or stopping a blood flow changing operation thereof in response to the switching of observation modes of the endoscope.

40. The examination method of using the endoscope according toclaim 39, wherein the observation modes comprise a first observation mode using visible-light illumination light, and a second observation mode using narrow-band illumination light, and wherein the blood flow changing step starts the blood flow changing operation in response to the switching to the second observation mode.

41. The examination method of using the endoscope according toclaim 35, further comprising a temperature monitoring step of monitoring a temperature of a mucous membrane of the living organ.

42. The examination method of using the endoscope according toclaim 35, wherein the temperature monitoring step comprises stopping the blood flow changing step when the temperature of the mucous membrane of the living organ rises above a predetermined temperature.

43. An examination method of using an endoscope inserted in a body cavity, comprising:

a blood flow changing step for causing vessels including capillary vessels in the near-surface of a living organ in a body cavity to change blood flow by irradiating a surface of the living organ in the body cavity with vibration energy with a vibration energy irradiator; and

an observation step of observing one of a vessel and blood flow changed in the blood flow changing step with the endoscope.

44. The examination method of using the endoscope according toclaim 43, wherein the blood flow changing step comprises warming the surface of the living organ in a manner out of contact with the surface of the living organ by irradiating the surface of the living organ with the vibration energy.

45. The examination method of using the endoscope according toclaim 43, wherein the non-contact warming step comprises irradiating the surface of the living organ with a microwave.

46. The examination method of using the endoscope according toclaim 43, wherein the blood flow changing step comprises starting or stopping a blood flow changing operation in response to the switching of observation modes of the endoscope.

47. The examination method of using the endoscope according toclaim 43, further comprising a temperature monitoring step of monitoring a temperature of a mucous membrane of the living organ.

48. The examination method of using the endoscope according toclaim 47, wherein the temperature monitoring step comprises stopping the blood flow changing step when the temperature of the mucous membrane of the living organ rises above a predetermined temperature.

49. An endoscopic apparatus for observing the inside of a body cavity, comprising:

an endoscope including an insert section to be inserted into the body cavity, an illumination window for directing illumination light therethrough and an observation window for observing an illuminated internal portion of the body cavity, arranged at a distal end portion of the insert section; and

a blood flow changing section for changing a blood flow of blood flowing through a vessel in a near-surface region of a living organ inside the body cavity by providing magnetic energy.

50. The endoscopic apparatus according toclaim 49, wherein the blood flow changing section comprises, at the distal end portion of the endoscope, a magnetic field generator for generating magnetic energy.

51. The endoscopic apparatus according toclaim 49, wherein the blood flow changing section comprises, external to the endoscope, a magnetic field generator for generating magnetic energy.

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